CATIA v.5, Assembly Design, Exercise 2 1 · CATIA v.5, Assembly Design, Exercise 2 3 a) b) Fig. 5. a) Coincidence Constraint, b) Contact Constraint Fig. 6 The base and supports The

CATIA v.5, Assembly Design, Exercise 2

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This exercise will show how to use Assembly Design to create a product from existing parts. Before you start this exercise, copy the files presented on list below (from Asd_ex1_files folder) to your local folder:

base.CATPart gear.CATPart shaft.CATPart support.CATPart

These files are set as Read only. You have to change attribute of these files to save any changes. Open Assembly Design workbench. A new Product structure appears. To change the name of the product use contextual menu (right mouse button), select Properties and change Part Number field in Product tab to Gear Assembly (Fig. 1).

Fig. 1. Properties window for Product

All parts for assembling were created earlier, so you can use Existing Component option to insert all parts

to assembly. Select icon from Product Structure toolbar and click Gear Assembly on the tree. The File Selection window appears. Find your local folder and select the file base.CATPart and press Open. New part will be listed on the tree and displayed on the screen (Fig. 2.).

Fig. 2. Insert existing component


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Repeat inserting for all parts (Fig. 3.). The part named support.CATPart should be inserted two times. You can use Compass to move and reorganize parts. It will allow you select axis, planes, surfaces easier. The product is ready to start create a constraint.

Fig. 3. Inserting parts to the assembly

Fix in space base part. Select Fix icon from Constraint Toolbar and select the base. Set Fix in space check-box as active (Fig. 4.).

Fig. 4. Fix in space the frame

Place both support on the base. You have to use Coincidence of axis and Contact of surfaces. Choose the

Coincidence Constraint icon from Constraints Toolbar and select cylindrical face of the holes on the

support and on the base respectively (Fig. 5a.), then choose Contact Constraint icon and select upper face of the base and bottom face of the support. You can use Compass to move and reorganize parts.

Now select Update icon to refresh constraints. The same options should be used to place second support (Fig. 6). Select Update to refresh constraints.


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a) b)

Fig. 5. a) Coincidence Constraint, b) Contact Constraint

Fig. 6 The base and supports

The shaft part will be positioned by axis coincidence and contact of specified surfaces.

Choose the Coincidence Constraint icon from Constraints Toolbar and select cylindrical face of the

holes on the support and on the shaft respectively (Fig. 7a.), then choose Contact Constrain icon and select the flank of the support and end face of the shaft shoulder (the ring on Fig. 7b.). Do not Update yet.

a) b)

Fig. 7. a) Coincidence Constraint of axis, b) Contact Constraint of a surfaces


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That two constraints are enough to define a proper orientation between the support and the shaft. However, you can define more constraints for each pair of elements.

Let us define additional constraint. First, define Contact Constraint between cylindrical surfaces of the hole in the support and on the shaft neck (Fig. 8.).

Fig. 8. Contact Constraint of two cylindrical surfaces

Then define Contact Constraint of the flank of the support and end face of the shaft shoulder on second side of the assembly (surfaces numbered by 1and 2 on Fig.9.). Choose the Coincidence Constraint

icon from Constraints Toolbar and select cylindrical face of the hole on the support and on the shaft respectively ( surfaces numbered by 3and 4 on Fig.9.).

Fig. 9. Contact Constraint of two surfaces

Now Update your assembly . The Update Diagnostic window appears (Fig. 10). There is information about all refreshed constrains. As you can see, some constrains are Solved and some are Ignored. This windows appears only if some errors occur. You can use that list to find the error and try to solve it.

1 2 3

4


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Fig. 10. Update Diagnostic window

Select the first position from the list. According to your choice the constraint sign will be selected on the screen (the orange colored sign on Fig. 11.).

Fig. 11. Recognition of error constraint

Use Edit button to check properties of that constraint (Fig. 12.).

Fig. 12. Constraint Properties window

Right values of all parameters mean that maybe dimensions are to be blamed - intersections occurs.

Select Clash option from Space Analysis Toolbar. Select Contact+Clash Type Between all components in Check Clash Window (Fig. 13.).


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Fig. 13. Checking clashes

The list of the contacts and clashes is the result of clash detection operation (Fig. 14.).

Fig. 14. Clash detection result

Because of intersection of some elements Clash type in List by Conflict Tab is important (contacts were defined by user). You can use Filter list=Clash to display clashes only. Select detected clashes one by one to see the result window (Fig. 15).

Fig. 15. Clash result window


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Close all windows. Select Sectioning option from Space Analysis Toolbar to recognize the intersection problem. The Sectioning Definition window appears. Select Geometrical Target option in Positioning Tab (Fig. 16a.). To define new orientation of the section plane select flank surface of the shaft neck (Fig. 16b). Then select Normal constraint Y check-box.

a) b)

Fig. 16. Section plane orientation The result window appears (Fig. 17.).

Fig. 17. Sectioning result window

Select Clash Detection option in Result Tab. The clashes will be displayed (Fig. 18). You can see two places, where the shaft and supports intersect. So there is a problem with shaft neck diameter and with longitude of the shaft.


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Fig. 18. Clash detection

Thus, you have to check dimension of each elements. You can do this by editing CATPart files directly from assembly. Double-click on the Shaft component on the tree – Part Design Workbench will be started automatically (Fig. 19.).

Fig. 19. Part Design Workbench in Assembly Design


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By double-clicking on the shaft you can access the base sketch for it (Fig. 20.). All dimension are available for changes. Find a radius 17 shown on Fig. 20 and change value to 15, replace the longitude dimension 265 by value 260. Confirm all changes.

Fig. 20. Dimension editing

Then double-click on the Gear Assembly product on the tree (Fig. 21.).

Fig. 21. Coincidence Constraint creation

System will back to Assembly Design Workbench. Now you can Update your assembly. This time all components are constrained correctly.

Place the gear part on the shaft by using Coincidence of the axis and Contact Constraints for surfaces (Fig 22.). This task should be performed by the user themselves.


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Fig. 22. Gear positioning

Add the component from catalog. The screws mounting both supports to the base will be selected from catalog.

Select Catalog option from Catalog Browser Toolbar. Catalog browser appears. Select ISO Standard on Current list, then choose Screws. Select ISO_4117_GRADES_A_B_HEXAGON_HEAD_SCREW, then ISO 4017 SCREW M20x40 STEEL GRADE A HEXAGON HEAD on the list. Double-click on it to import the screw to the assembly (Fig. 23.).

Fig. 23. Inserting the screw


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You can insert 3 next screws by using the same procedure or by using Copy-Paste option (Fig. 24.).

Fig. 24. Multiply inserting

To finalize the assembly it is necessary to build proper constraint for all of the screws (Fig. 25.).

Fig. 25. Positioning the screws

Applying the material for components. The user can apply the material during part generation, however it is possible to provide this operation in assembly too. CATIA offers intermodule operations. Applying material in assembly workbench means update the CATPart file of the component automatically.

Select Apply Material icon . Press and hold Ctrl key, then select all components on the tree. Next select Steel material from Metal Tab in Library of materials. Now you can expand the tree component to see Steel element added to the tree (Fig. 26.).


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Fig. 26. Applying material

Now you can perform analysis. For example to check inertia properties click Measure Inertia option in Measure Toolbar. Select Gear Assembly Product on the tree to define properties for whole assembly. The inertia properties will be displayed on window and some geometry will be placed on screen (Fig. 27.).

Fig. 27. Measuring inertia


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Click the Measure Between option to check distance between top surface of the Base and the axis of the Shaft (Fig. 28.).

Fig. 28. Measure between

If you want to keep the results of measuring activate Keep measure check-box. All measures will be added to the tree in Applications element (Fig. 29.).

Fig. 29. Keep measure result on the tree

Documents

CATIA v.5, Assembly Design, Exercise 2 1 · CATIA v.5, Assembly Design, Exercise 2 3 a) b) Fig. 5. a) Coincidence Constraint, b) Contact Constraint Fig. 6 The base and supports The